After his wife's car plunged into a river, Stacy Horton had an agonising decision to make: rescue her or their teenage son. [via dailymail]

His wife Vanessa had escaped from the car but was crying for help as she struggled to keep her head above water, while their son Silva, 13, was still trapped inside the sinking vehicle.

With time to save only one, Mr Horton dived into the river.

In the evening darkness, he could only just still see the Mazda station wagon, which was already three feet below the water and sinking fast nose first, with the glow of the tail-lights fading into the darkness.

'I tried to get down and get him [Silva] but I couldn't - it was just too deep,' said Mr Horton yesterday. 'And Vanessa was going under.

'I made a call to pull my wife to safety. I looked back and I could see the tail-lights, but it was too far and I couldn't get him. Horror: Stacy Horton saved the life of his wife Vanessa, but their son Silva, drowned in the accident

'I just had to accept the fact that he had gone.

'Instead of going down and risking my life as well as my wife and son's, I chose to take Vanessa back and sat on the shore praying. It was all I could do.'

Silva's friend and the family dog, who had also been in the car, had managed to scramble to safety by the time Mr Horton arrived at the scene, two minutes after the car had entered the Whanganui River, north of Wellington, New Zealand.

The tragedy began when a group of children broke the Hortons' letterbox at their home in Whanganui before running off.

Mrs Horton, 35, clambered into the station wagon with Silva and his friend to give chase, while her husband followed in another car.

He caught up with his wife's car not far from their home. It is thought she had found the group of children and stopped to confront them when the car rolled down the bank into the river.

After Mr Horton had made his heartbreaking decision to drag his wife to safety, police and firefighters, summoned by passers-by, dived into the murky water to try to free Silva. However, by then, even reaching the vehicle proved impossible in the darkness.

'We tried everything but to no avail,' said senior fire officer Gary Wilson. 'It was a long shot but it was worth the risk to try and save him.'

Police spokesman Kim Perks said: 'It was a very tough call for Mr Horton. I certainly would not have wanted to be in his shoes.'

Divers managed to recover Silva's body on Sunday. Mrs Horton said she was comforted by her belief that Silva, a committed Christian, was now in a better place.

'He'll be having a party at the moment,' she said.

Mr Horton said: 'He was outgoing and anyone who he came across he made friends with.

'Even anyone he didn't like, if he saw they were in trouble he would go and help them.

'He rammed as much into his life as anyone could possibly do.

'It's just a freak accident. We can't blame anyone. I've forgiven the kids who were wrecking our letterbox.'

'I love those kids and I know how they will be feeling,' said Mrs Horton. 'I don't hold them responsible.'

The couple said Silva's funeral on Thursday would be a celebration of his life and they planned to release 13 balloons, one for each year they spent with him.